In
the United States, the incidence of preterm labor is around 12% of live births,
which is higher than in most countries (Tucker, 2004). A premature birth is
considered any delivery of a fetus before completed gestation at week 37. For
the prevalence of preterm labors that are seen in the United States, the
epidemiology of this condition is understudied in my opinion. In 2002, preterm
birth accounted for two thirds of all infant deaths in the United States (William,
2006). I was a premature baby, born at 32 weeks, and luckily was very healthy.
I also have a close friend with twin babies that were born at 26 weeks, which
is far too early to not encounter any issues, but luckily they had none.
There
are not a ton of preventative treatments for premature delivery, however, a
recent study has been done that may link the presence of bitter taste receptors
on cells in the smooth muscle to relax the uterus when preterm contractions
begin (Akst, 2017). The mechanism that allows this to happen is the activation
of the receptors may lead to calcium channels changing the ion gradient within
the muscle. This was discovered when a scientist from University of
Massachusetts Medical School, Ronghua ZhuGe, found bitter taste receptors on
the smooth muscle of the airway and began researching the functional mechanism
that would explain this location (Akst, 2017) It turned out that the activation
of this type of taste receptor lead to a relaxation of the cells of the airway.
The researchers began to explore the benefits of this same relaxation induced
by bitter taste receptors in the uterine wall, since it is made up of smooth
muscle, and in fact they found that these receptors do reside there (Akst, 2017).
After experimenting with the muscle cells of the uterus, the same mechanism of
relaxation was discovered. However, the relaxation of actively contracting
uterus’ did not have the same outcome.
Although
this study was completed in 2013 and still has a wide range of unknowns, I
believe it is a lead to some cure or treatment for preterm labor. The
conclusion that I made while reading the article written by Jef Akst, was that,
there is an association with bitter taste receptors and calcium-activated
potassium channels that lead to relaxation of certain smooth muscle types. It
is important to prevent preterm labor, because unlike myself and my friend’s
twins, majority of premature babies have developmental or other health issues
that stay with them through out their lives.
Akst, J. (2017, October 1). Bitter Taste Receptors in
Uterus May One Day Help
Prevent Premature Birth. Retrieved from http://www.the-
scientist.com/?articles.view/articleNo/50402/title/Bitter-Taste-Receptors-in-Uterus-May-One-Day-Help-Prevent-Premature-Birth/'
Callaghan, W., MacDorman,
M., Rasmussen, S. , Cheng Qin, Eve M. Lackritz,
Pediatrics Oct 2006. The Contribution of Preterm Birth to
Infant Mortality
Rates in the United
States118 (4) 1566-1573
Tucker,
J., & McGuire, W. (2004). Epidemiology of preterm birth. BMJ :
British
Medical Journal, 329(7467),
675–678.
Very cool! My initial reaction to taste buds on smooth muscle is... why? Why would we have bitter taste buds on uterine smooth muscle tissue, how did researchers come to this discovery, and how did they test this theory?
ReplyDeleteI am aware that it is common in pregnancy to experience heightened or altered sense of taste/smell due to hormone changes and have wondered if there is an adaptive reason. Similarly, the investigation of possible taste buds in smooth muscle goes hand-in-hand with the inquisition of evolutionary purpose. I can't help but read this and think... why, but aside from that, the potential benefit of this research could be profound. Preterm labor is dangerous for baby and mom and the application of a calming effect on the smooth muscle of the uterus could help moms carry their babies for longer and reduce risk associated with premature delivery. Additionally, though mentioned not effective on actively contracting muscle, it may be plausible that utilization of these taste receptors as therapy could ease menstrual cramping and overactive/stimulated smooth muscle as well. Such an odd and fascinating discovery... well done!
I think in cases such as this it's good to remember that not every trait in an organism has a specific evolutionary purpose in and of itself. In fact, many traits of an organism are cladistic. They are what's considered 'evolutionary hold-overs' of traits found in common ancestors. It would be very interesting to see if similar bitter taste receptors in this location are also present in other primates, mammals, or vertebrates. How far might this date back? I was not able to find any studies that looked into bitter taste receptors in the areas mentioned in other animals, but it would be very interesting to investigate further!
DeleteVery good point. Just interesting and thought provoking to question. I forgot to add the source I used/read that contributed to my comment -
DeleteTaste changes during pregnancy. (1986). Journal of Nutrition Education, 18(5), 214. doi:10.1016/s0022-3182(86)80047-4
Using bitter taste receptor to prevent premature birth is really cool! I didn’t know bitter taste receptors exist anywhere else besides the tongue. I tried looking more into it, turns out, we also have sweet taste receptors in the uterus as well! Not only can we find bitter taste receptor in the uterus, it can also be found in the lungs. I came across an article discussing on the potential treatment of asthma or chronic obstructive pulmonary disease (COPD) using bitter taste receptors to open up the airway. It looks like the relaxation effect of activated bitter taste receptor can be beneficial not only for premature birth preventions, but for treating other diseases as well.
ReplyDeleteRobinett, K. S., Koziol-White, C. J., Akoluk, A., An, S. S., Panettieri, R. A., & Liggett, S. B. (2014). Bitter Taste Receptor Function in Asthmatic and Nonasthmatic Human Airway Smooth Muscle Cells. American Journal of Respiratory Cell and Molecular Biology, 50(4), 678–683. http://doi.org/10.1165/rcmb.2013-0439RC
I found this blog post and its comments incredibly interesting. If research proves that this is an effective treatment for preterm labor, I am curious if it would be applied to all pregnant women after a certain point in their pregnancy as a precautionary measure, or if it will only be applied to those women who are already experiencing preterm labor. I would imagine that there is a fine line between this therapy being effective and ineffective, depending on how advanced the labor is. So, my thought is, if this treatment is found to be effective and easily done, would it be able to be applied prior to the start of the labor? Would there be negative effects of doing so? It would be very interesting to see further research done on this.
ReplyDeleteAfter reading your post, I was curious if any other taste receptors have been studied. I found an article that discussed how bitter and sweet taste receptors influence immune defense responses in respiratory epithelium. To be completely honest, I was unaware that taste receptors existed elsewhere in the body! My niece suffers from terrible asthma that causes her to develop pneumonia or a new lung infection every month. Knowing that these taste receptors could be used for treatment of asthma makes me hopeful that maybe they can be used to help her!
Lee, R.J., Hariri, B.M., McMahon, D.B., Chen, B., Doghramji, L., Adappa, N.D., Palmer, J.N., Kennedy, D.W., Jiang, P., Margolskee, R.F., Cohen, N.A. (2017). Bacterial d-amino acids suppress sinonasal innate immunity through sweet taste receptors in solitary chemosensory cells. Science Signaling, 10(495).